• Horticultural Science & Technology
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• v.34 no.1
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• pp.1-14
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• 2016

Heat stress is an agricultural problem for Gerbera jamesonii, and it often causes poor seedling growth, reduced flower yield and undesirable ornamental characteristics of flowers. However, little is known about the effect of heat stress on the morphological, physiological and biochemical characteristics of gerbera plants. Here, the responses of six cultivars of Gerbera jamesonii to heat stress were investigated. Under a 1-d heat treatment at $45^{\circ}C$, the leaves of gerbera cultivars showed yellowing, wilting, drying and death to varying degrees. The heat treatment also resulted in increased electrical conductivity, decreased soluble protein and chlorophyll contents, and the accumulation of malondialdehyde (MDA) and proline in leaves. Moreover, heat tolerance differed among the six tested gerbera cultivars. Our results demonstrated that among the six gerbera cultivars, 'Meihongheixin' is a heat-resistant cultivar, whereas 'Beijixing' is a heat-sensitive one. 'Shijihong' and 'Linglong' are relatively heat-resistant cultivars, and 'Dadifen' and 'Taiyangfengbao' are relatively heat sensitive.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.374-376
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• 1996

1992년부터 국내 주요 거베라 재배지역에서 Phytophthora속 균에 의한 역병이 발생하였다. 이병주는 뿌리조직이 파괴되어 급격히 시들며 말라죽는데 지제부의 잎자루는 수침상으로 검게 썩는 병징을 나타낸다. 총 47개 균주를 이병주에서 분리하여 균의 형태적, 배양적, 생리적 특성 등을 조사한 결과 모두 Phytophthora cryptogea로 동정되었다. 각 지역에서 수집된 20개 균주중 유성생식형 A1과 A2는 각각 8균주와 4균주였고 8개 균주는 불임성(sterile)이었다. 병원균은 7개 거베라 품종에 모두 강한 병원성을 나타내어 품종간 차이를 관팔할 수 없었다. P. cryptogea는 아직 국내에 기록된 바가 없는 식물병원균으로 거베라 역병균으로 처음 보고한다.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.110-115
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• 2011

To examine the availability of onggi (earthenware) as a floral vase, we compared the vase life of cut gerberas (Gerbera jamesonii) with generally used vases made of glass and porcelain. After holding cut gerbera 'Honeymoon' and 'Golden Time' in vases made of glass, porcelain, and onggi containing holding solution (tap water or preservative solution), vase life, fresh weight, and water uptake of cut flowers, and total number of microbes in holding solution were collected. In onggi vase, vase life of both the cultivars was longer than the other vases and floral preservative prolonged vase life compared with tap water. Cut gerberas applied with preservative solution in onggi vase maintained their ornamental value for more than 14 days. Cumulative water uptake by cut gerberas was greatest in onggi vase, where 'Honeymoon' and 'Golden Time' absorbed water by 19.2 and 15.8 mL, respectively, for 10 days. Fresh weight of cut flowers in onggi vase was greater than those of the others, and the preservative solution delayed the reduction of fresh weight compared with tap water. Especially, onggi vase with preservative solution maintained 89% of the initial fresh weight at the 8th day of the treatments due to smooth water uptake with comparison with 71% in porcelain. Total number of microbes in the holding solution was smallest in onggi vase. At the 8th day, microbes number in onggi vase was 435 cfu/mL, that was 20-30% level of those of glass and porcelain vases. In conclusion, onggi vase inhibited microbial proliferation in holding solution, maintained water uptake by cut flower, and delayed bending of flower stalks due to vascular blockage, and then prolonged vase life in gerbera. Therefore, onggi with numerous micropores will be a good material for flower vase and preservative solution can improve its function.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.76-84
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• 2008

This study was conducted to find out the cause of discoloration after pressing yellow-colored flowers. Plant materials used were Lilium Asiatic Hybrids, Oncidium spp., Rosa hybrida, $Tulipa{\times}gesneriana$, Antirrhinum majus, Dianthus caryophyllus, Freesia hybrida, Zantedeschia elliottiana, Gerbera jamesonii, Helianthus annuus, and Ranunculus asiaticus. Thickness, ratio of length to width, and water content of petals did not considerably affect discoloration of pressed flowers. Expression of yellow color in petals was caused by carotenoids in Lilium Asiatic Hybrids, Oncidium spp., Rosa hybrida and $Tulipa{\times}gesneriana$, by flavonoids in Antirrhinum majus, Dianthus caryophyllus, Freesia hybrida and Zantedeschia elliottiana, and by coexistence of carotenoids and flavonoids in Gerbera jamesonii, Helianthus annuus and Ranunculus asiaticus. Carotenoids that expressed yellow color in petals affected significantly on discoloration in pressed flowers containing carotenoids alone or both carotenoids and flavonoids. However, discoloration was hardly ever found in yellow-colored species as affected by flavonoids. Dark treatment was effective for almost perfect preservation in color of pressed flowers, while light treatment resulted in severe discoloration.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.59-66
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• 2011

This study was conducted to investigate the effect of vase material and floral preservative treatment over time on flower color, leaf color and flower size of cut flowers Rosa hybrida 'Aqua' and 'Corvernet', and Gerbera jamesonii 'Honeymoon' and 'Golden Time' stuck in a glass, porcelain, or onggi (pottery with a dark bronze glaze) vase containing either tap water or a floral preservative solution. The ${\Delta}E$ values in flower color of 'Aqua' rose at 8 days after treatment with a floral preservative in onggi and porcelain vases were low. The ${\Delta}E$ value of 'Covernet' rose treated with floral preservative in an onggi vase was the lowest and L value was the closest to that of petals of cut flowers at just before treatment (control). The ${\Delta}E$ value of 'Honeymoon' gerbera treated with a floral preservative in an onggi vase was the lowest and a value of 58.81 and b value of 34.29 were the closest to that of the control group as color of cut flowers in an onggi vase was similar to the color at the beginning of treatment. The ${\Delta}E$ value of 'Golden Time' gerbera treated in an onggi vase was significantly lower than that in a porcelain or glass vase and a value of -7.81 treated with a floral preservative solution in an onggi vase was the closest to the control and b value was high in an onggi vase as well. The L, a, and b values in leaf color of roses were similar to each value of the control and ${\Delta}E$ value of 3.25 measured in an onggi vase was lower than that in a porcelain or glass vase. Flower diameter of 'Covernet' and 'Golden Time' roses treated with a floral preservative in an onggi vase was greater than that in other treatments. From these results, the floral preservative applied to a holding solution is assumed to improve the quality and freshness of cut roses and gerberas by inhibiting microbes propagation and by promoting uptake of water and nutrients. The onggi vase with fine pores will promote the expression and maintenance of flower and leaf colors and may increase flower diameter by high air permeability.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.97-103
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• 2001

The rate of gerbera (Gerbera jamesonii Bolus.) leaf damaged by Liriomyza trifolii larvae was lower than that by adults. The adults began to be attracted to yellow sticky trap immediately after transplanting and increased gradually up to early August followed by low population density from middle to late August. In the second year, adults began to be attracted from late April after transplanting and increased abrubtly from middle May and the high density was maintained till early truly. The density decreased, however, from middle July, and then followed by the high density again early September and late October The seasonal fluctuations of larva and pupa were similar to that of adults and the peaks of pupa occurred one week later than that of larvae. Larva infected by parasitoid were observed 4 weeks after transplanting. Parasitism was 65% in average from early July to late August but decreased to 50% from early September. Number of trapped adults was the highest in the yellow sticky trap among the five different colour raps. Catches at 30~60 cm above soil surface were significantly greater than that at 90 cm.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.149-153
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• 2001

We surveyed on the host plants of Fungus gnat, Bradysia app. and found 21 species in the greenhouse and field. These are as follows: Cucumis sativus L., Cucumis melo L., Citrullus lanatus T., Cucurbita moschata F., Lycopersicon esculentum M., Capsicum annuum L (Pepper), Capsicum annuum L (Paprika), Lillium longiflorum T., Dianthus caryophyllus L., Rosa hybrida H., Gerbera jamesonii B., Chrysanthemum morifolium R, Phalaenopsis schilleriane R., Gladiolus grandiflours H., Zingiber officinale R., Cnidium officinale M., Canavalia gladiata DC., Angelica utilis M., Polygonatum odoratum D., Pinus densiflora S., and Pinus thunbergii P. Fungus gnat larvae cause damages to the root and promote decay and wilt by feeding on the roots and burrowing in plant tissue.

• Research in Plant Disease
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• v.28 no.4
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• pp.231-236
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• 2022

Oxypetalum coeruleum, commonly known as Tweedia, is a perennial herbaceous plant of the Apocynaceae family native to southern Brazil and Uruguay. Tweedia plants are grown as one of the most popular ornamental flowers for floral arrangement in Korea. In May 2021, several tweedia plants in a single greenhouse in Gimje, Jeollabuk-do were found to show virus-like symptoms including necrotic rings, vein-clearing, chlorotic mottle, and mosaic on the leaves, and necrosis on the stems. Here, we have identified tomato spotted wilt virus (TSWV) in symptomatic tweedia leaves by applying high-throughput RNA sequencing. In the result, a single infection by TSWV was verified without mixed infections of different virus species. To confirm the presence of TSWV, a reverse transcription polymerase chain reaction was performed with a specific primer set to the N gene of TSWV. The complete genomic sequence of L, M, and S segments of TSWV 'Oxy' isolate were determined and deposited in GenBank under accession numbers LC671525, LC671638, and LC671639, respectively. In the phylogenetic tree analysis by maximum likelihood method, 'Oxy' isolate showed a high relationship with TSWV 'Gumi' isolate from Gerbera jamesonii in Gyeongsangbuk-do, Korea; for all three RNA segments. To our knowledge, this is the first report of TSWV infection of O. coeruleum in Korea.